Color Saturation (MD)

Every image toolkit has a saturation knob, and most of them are the same blunt HSV slider under a different name. MdColorMod's mdColorSaturation is a bit more interesting than that, because it lets you pick which color space does the scaling. That one dropdown is the whole difference between "made my image more colorful" and "made my image more colorful without wrecking the skin tones."

How it works

You give it a Scale multiplier and it multiplies the chroma - how far each pixel sits from the gray axis - while leaving lightness alone. The Color_Space dropdown changes what "chroma" means:

• Native - HSV. The classic blunt approach. Scales saturation in HSV space. Fast, familiar, and it can shift perceived brightness on saturated colors.
• CIE Lab/Lch - scales chroma in LCh, where the color is split into Lightness, Chroma, and Hue. This keeps perceived lightness stable, which makes it the safer pick for skin, fabric, and anything where you want richer color without the image feeling darker.
• CIE Yuv - scales the two chroma-difference components of the video-standard Yuv space. The engineering heritage pick; behaves differently from both and can be fun to push.

The code paths are all GEGL-style conversions implemented in pure torch - no GPU-heavy dependencies, no models. Alpha is preserved, and like every node in this pack you get an optional mask to confine the adjustment, plus batch processing.

The inputs that matter

• image - your IMAGE.
• Scale - FLOAT, 0 to 10, default 1. 0 is fully desaturated, 1 is untouched, above 1 boosts. You almost never need above ~2.
• Color_Space - the dropdown above. Default Native; switch to CIE Lab/Lch when skin or fabric is in frame.
• mask - optional, restrict to a region.

Single image output, straight into Preview/Save or the next node in the chain.

Install

Same pack as all the MdColorMod color nodes - zero dependencies, no model downloads:

cd ComfyUI/custom_nodes
git clone https://github.com/MdONeilsl/ComfyUI-MdColorMod

Then restart ComfyUI. Or search "MdColorMod" in ComfyUI Manager.

Where people get burned

The trap is thinking saturation is linear in the slider. A Scale of 1.5 in Native mode is a lot - colors clip fast once they leave the sRGB gamut, and the node clamps at 0–1, so you get flat, blown-out reds and no warning. If you want punch, live in the 1.15–1.35 range. And if your goal is a subtle desaturate for that "moody" look, 0.85–0.95 in LCh beats 0.8 in HSV every time - the HSV path darkens as it desaturates, and that's usually not what you meant.